Interlocking system for railroads



June28, 1938. s. N'. wlGH-r INTERLOCKNG SYSTEM FOR RAILROADS Filed April 2l, 1934 k'7 Sheets-Sheet 1 INVENTOR 5. 7i.

AT ToRNY June 28, 1938.' s. N, wlGHT INTERLOCKING SYSTEM FOR RAILROADS Filed Apri-1 2l, 1934 '7 Sheets-Sheet 3 mmov mov buoi lomvo En no m.

June 28, 1938. s. N. wlcsl-ITv INTE'RLOG'KING SYSTEM FOR RAILROADS Filed April 21, 1934 '7 Sheets-Sheet 4 NN 2b June 28, 1938. s. N. wlGHT INTERLOCKING SYSTEM FOR; RILROADS 'Filed April 2l, 1954 '7 Sheets-'Sheet 5 Mdm INVENTOR /w ATTORNY June 28, 1938.

s. N. wlGHT INTERLOCKING SYSTEM FOR RAILROADS Filed April 21, 1954 7 Sheets-Sheet 6 INVENTOR June 28,- 1938. s. N. wlGHr INTERLOCKING SYSTEM FOR RAILROADS ,7 Sheets-Sheet 7 Filed April 2l, 1954 T15 points on the miniaturetrack layout which cordegree of Safety. l

F30 nal to clear to allow the passage'of traflicprovid- Patented June 28, l 2,1

t UNITED t STATES PATENT vOFFICE o t 2,121,846 Y v INTERnooKING SYSTEM Fon BAiLnoAns Sedgwick N. Wight, Rochester, N. Y., assigner to general Railway Signal Company, Rochester,

Application April 21, 1934, Serial No. 721,696

45 Claims. (Cl. 246-134) This invention relates to interlocking systems selected by suitablecontacts on theiroute buttons, for railroads, and more particulary pertains to so that following the actuation of the buttons at such a system in which a miniature track layout the vopposite ends of a route, arelay whichcorin a control oice has located thereon the conresponds to that particular route is energized h y A trollingl buttons or levers for setting up the dewith a polarity in accordance with the direction *"5 Sred routes, arldn Which allof the interlocking of traffic to be established over such route. This, between the various traic controlling devices Lis [route relay, thus selected; is employed to set up 4tooouflplisl'lef by the proper selection of electric individual controls for the track switches yinpv circuits. volved in that route and for the signal governingl lo The present invention Contemplotes that a trahie over such route. These individual controls miniature track layout is located in the central are transmitted to the track Switches andsignal's control oice which corresponds to the actual in the actual track laygugwhicharedinterlpcked 'track-layout in the eld. On this miniature track by Cimuits that are preferably located adjacent layout are located route buttons or levers at those to the trackrlayout so as to' provide the greatestA Y c fl5 :respond to the signal locations on the actual Thus, one Object of the present invention'may track layout.. In order to'establish the movement be Said to reside in an arrangement of control 0f traffic in a particular direction over a' particu' wherein the operator is associated ywith the actual lar traokWaY foute the' o perator aCPuateS the' trackway conditions in termso'f completen-routes,

buttons or levers in the desired route 1n a direcand directions of tramo movement which are the 220 @on correspondmg to the deslred traicdlrec' desired ultimate ,resultsf instead of in terms of non' n the differentiated functions ofA such results.

Instead of providing individuali switch and sig" Other objects purposes andcharacteristic fea- ;nal control levers which are lnot on the miniature `tures of the present nventon Wm b in part Ob n i f2; track diagram, as 1s the usual practice, the actuavous from the accompanying drawings and in 25 @tion of-the route vbuttons-fat the two opposite t n. partv pointed out, as the description of the invenends of a desired route serve to both control the tion progresses track swltches m the field to' the required posl" `In describing the invention in detail, reference tions for that route and to cause the proper sig- Wm be made to the accompanying drawingsvn which like reference characters designate `the same parts throughout the several views; in which like letters in the reference characters designate similar functions or relationships with the distinctiveness between suchreference characters 435 Afrom the miniature track diagram in order 4to provldedgby mens? of dlstmctlve prece-dm? nu? i.

accomplish switch controls, but ymay maintain merals; m Whlch hke precedmg I mmeralsjm the his attention along the desired route andactuate reference Characters when apphed to" dlfferent Such route determining buttonsordevers as are lletters, represent the linclusion of such devices located in that route. within a particular group.; and in-which:-`

Also, the arrangement contemplatedin accord- Figs 1 and 2 When'placeq end t0 end Constiance with the present invention has a distinct adbut? an mterlockmg System .lnustl'vated dafgram e vVantage over previous route ylever Systems in that l matically and constructed in accordance with the formerlyaseparate levertwas required foreach of present nVentOn aS-appled t0 a Simple track 'A ,ing it is safeto do so.

Such an organization, as contemplated in accordance with the present invention, has thevadvantages over the usual practice in that the opii eratoris not required todirect his attention away 645 the possible routesr so that a` large number of layout including GWG CTOSSOVGTS and af tu1'n'0ut45 t levers would be required in` connection with each track; v vsigna] loation, The present invention prefer- Fig. 3 illustrates the 4route selecting circuits i ably provides but a single buttonfat Veach signal 'Which are employed at the field location for the location and a route is determined by the actua- 'track layout illustrated and Which Connect to tionl of the buttons at thetwo'opposite ends'of the signal Control Wires of Fig. 1 in place ofthe l50 fsucli route. Fig. 2 where such control is merely indicated;

The means employed in the lembodiment ofthe Fig; 4 illustrates the detail switch control means present invention to accomplish the settingfup for a Single Switch, it being understood that Simof the routes following the actuation of theroute `ilar apparatus would be employed for each switch 55 buttons is provided in they forni of electric circuits -in the trackdayout,l and it being understoodzthat F55 this Fig. 4 shows the detail of the switch control merely indicated conventionally in Fig. 2;

Fig. 5 illustrates the individual signal control and selection for certain of the signals, it being understood that similar controls would be prol vided for each of the remaining signals in the track layout and it being understood that this Fig. 5 taken with Fig. e shows the detail of the signal control merely indicated in Fig. 2; and

Fig. 6 illustrates a modied form of switch control to accomplish certain additional features` in accordance with the present invention.

Fig. 7 is a first modification of Fig. 1.

Figs. 8, 9 and 10 illustrate a second modication of Fig. 1.

Instead of showing a complete circuit arrangement by placing a large number of sheets side by side, a simplified method of disclosure has been employed wherein all of the control circuits for any one relay are shown in a continuous relationship; while all of the circuits which that relay may control are distributed between the several sheets of drawings upon which that relay is shown in block form.

For the purpose of further simplifying the illustration and facilitating in the explanation thereof, the conventional parts and circuits con- Ystituting ,the embodiment of the invention have been shown diagrammatically and certain conventional illustrations have been employed, the drawings having been made more with the idea of making clear the purpose and principles of the present invention together with its mode of operation than with the idea of illustrating the specific construction and arrangement of parts that would probably be employed in practice.

The various relays and their contacts are illustrated in a conventional manner and symbols are employed to indicate connections to the terminals of batteries or other suitable sources of electric current` supply instead of showing all of the wiring connectionsto such terminals.

The symbols and are employed to indicate the positive and negative terminals respectively of suitable batteries, or other sources of electric energy; and those terminals with` which these symbols are used are presumed to have current flowing from the positive terminal designated to the negative terminal designated The symbols (B+) and (B-) indicate connections to the opposite terminals of suitable batteries, or other sources of energy which have central or intermediate taps designated (CN), and the circuits with which these symbols are used, may have current flowing in one direction or the other depending upon the particular terminal used in combination with the intermediate tapk designated (CN). For convenience in` the illustration, certain of those terminals which are designated (CN) are considered to be connected together in place of showing a common wire connection as would be necessary in practice. The symbols employed with any one circuit presumably designate the terterminals.

Where groups of devices are referred to in a general way, such devices will be designated by the letters or preceding numerals characteristic of such group instead of citing each specific reference character of the group.

Apparatus In the accompanying drawings, the invention has been shown applied to a simple track layout including a stretch of double trackhaving two crossovers and one turn-out track (see Fig. 2); but it should be understood that the invention is not limited, as thus shown, to the control of the switches and signals of such a `simple track layout, but may be extended for any desired number of switches and signals and may be readily applied to all types of track layouts commonly found in interlocking plants.

The stretch of double track includes main line rails Zilli and main line rails while the turnout track includes rails 262 (see Fig. 2). The main line 2M) is connected to the main line 20| through switches 2TS and STS forming opposite ends of one crossover, and track switches 4TS and 5TS forming the opposite ends of a second crossover. The turn-out track 202 is connected to the main track 20| by the track switch ITS.

The track switches ZTS, ETS, lt TS, STS and ETS are respectively operated by power switch machines ZSM, SSM, QSM, ESM and ISM, which switch machines may be of any suitable type, such for example, as disclosed in the patent to W. K. Howe, Patent No. 1,466,903 dated September 4, 1923.

A signal lUA is provided to control east-bound traflic over the main track 20|); while a signal 39A is provided to govern west-bound trafc over the main track Z. A lower arm signal IEIB is provided to control east-bound trafflce from the main track 2li@ over the crossover having switches ATS and ETS onto the main track 20|; while a lower arm signal SDB is provided to control westbound trafc from the main track 200 over the crossover having switches ZTS and STS onto the main track 20| A signal 26A is provided to govern east-bound traic over the main track 20| up to a signal WEA, which then governs east-bound traflic over the main track 20|. Both the signal 20 and the signal 40E are provided with lower arm diverging route signals 20B and llllEB respectively. The signal 40E is also provided with a call-on signal MEC which governs trafc either over the main track or the turn-out track independently of vtrack occupancy conditions as hereinafter more specifically pointed out.

The signals 5U and llWA govern the westbound trafc over the main track 20|, while the lower arm signal MJWB governs the diverging route from the main track 20| onto the main track 20|] over the crossover having switches 4TS and STS.

The section of track between the signal l0 and the signal 3i! forms'a track circuit section and is provided with a track relay 24T anda suitable track battery (not shown). Similarly, the main track 29| forms a track circuit section between the signal 2U and the signal Ml and is provided with a track relay 35T and the usual track battery (not shown).

A section of the main track 20| forms a track circuit section between the signal 4|) and the signals 50 and Sli, and is provided with a track 'relay lT and the usual track battery (not shown).

The main track 205| is probably provided with a track circuit section east of the signal 30 and the usual automatic signalling although this is a matter determined by' the conditions er a particular situation in practice, and therefore has not been shown. The main track ZlIIj Vandthe turn-out track 202 have extending track circuity divided or lengthened'as desired, andy arranged in accordance with any of the usual practices. y

*The track switches of a crossover are controlled together, as indicated by the dotted lines in Fig. 2, Therefore, a single lock relay 23L is associated with the trackswitch'es Z'I'S `and STS; a

singlelock relay 45L is associated with the track switches 4TS and 5TS; and, a single lock relay IL is associated with the track switch TTS. Each Y of vthese lock relays L is 'a neutral relay with slow release and quick pick-up characteristics.

The controls directed tothe trailc controlling devices illustrated in Fig. 2 have been shown as dotted lines which merely indicate the yultimate destination of the controls originating in Fig. l,

it being understood that the details and inter.-` .relation of such controls indicated by these dotted linesV are shown in detail in other figures of the drawings, as more specifically pointed out hereinaften lWith reference to Fig. l of the accompanying drawings, thecontrol oiiice is illustrated asincludingja miniature track diagram having a track layout' corresponding to the' actual track layout vinithe field.

i A movable miniature track switch point is prefyerably provided to represent each of the trackl "switches of the track layout in ther iield, such as miniature switch points k2ts, Tits, 4ta, 575s, and lts, These miniature track switch points may `indicate the actual positions of their corresponding switches in a manner disclosed in my pending application,l Ser. No. 431,748, filed February 27, 71930. However, ina system as provided by the present invention, lit' is desirable 4to have these :miniature switches controlled in accordance withthe proposed ,route as set up bythe operator in va manner disclosed herein. ,A y Associated with each of theminiaturetrack switch points. is a lock light which indicates ,whenever that ktrack switch is locked against operation. Although such lock lights have not been illustrated in connection withy the 4miniaturetrack switch points in Fig. l, such Aa lock Y light has been speciii'cally,v illustrated for the disclosed.

track switch irs es indicator 1| in Fig. d df tire accompanying drawings where its control is Y At each point on this Iminiature track lay-'out :corresponding to the point on the actual'ltrack lay-out where signals are located, is located a suitable rotary control lever or button designated by the lettery reference characters RB and indicated as associated with the corresponding sigvnals in the rleldY by the preceding numerals which 'correspond with the numbers of such signals.

These rotaryroute buttons RB'have been shown as having arrows thereon which indicate the existing posit-ion of the buttons which are normally in vertical positions, but any other suitable method of designation` may -be employed. When a route button isrotated to the right, it designates the setting up of traliicinv the right hand direction; and, when a route button lis rotated to the left it designates the setting up of trarlic in a left hand direction. Each rof these route buttons A'RB operate suitable contacts.

-llllRB operates contactsI, 42,143 and '44p-'the route button 5BRB operates contact 5I; and the route button llRB operates contactIiI. Each route button RB, when rotated in a particular direction, operates its contactsv in the same direction to contact closing positions. l

It is or course to be understood that "although I rotary route buttons have been'illustrated and contemplated in accordance with the present embodiment `=of the invention, that other suitable manually operable contact means might `'be employedsuch as a three-pOSitiOn'snap switch or the like. Y

Although no signalindica'tors have been vshown on the track diagram, it is contemplated that a signal indicator is associated with each route button representing a signal location and Vis caused to be illuminated when itsV respective signals are cleared, so that the operator is continuouslyV advised as to the trackway` conditions.

When two route buttons` RBA are operated Iat the opposite ends of a route in the same direction, a route relay is' picked upA which corresponds to thatparticular route and thereby prevents all other r-oute relays of conflicting routes from being energized by reason'of its contacts which are included in the pick-up circuits for all such conflicting route relays. Each of these route relays is energized with a polarity in accordance with the direction of traic to vbe set up, allfof which will be explained more in d-etail hereinafter, it being sumcient for the present to merely enumerate the route relays thus controlled and point out that these` relays are'preferably of the polar-neutral type in which the neutral contacts arer picked up only while the relay is energized and in which the polar contactsy remain -in their last actuated positions.

A route relay I {1 -30 (see Fig. l) controls the f' traic between signals Ill and 30 (see Fig. 2) and is provided with contacts I5, I8, 52, 53, 54 and v55. A route relay 20-30 controls traic betweenthe signals 26 vand 3l) over the crossover including switches ZTS- and STS, and isprovided with contacts I3, "5,126, 56, 51, 58 and 59. A routevrela'y Iii-4I) controls trailc'between the signals IB andA 40 over the crossover including switches4TS and 5TS, and is providedY with contacts I4, |9521, 46, 4l, 48 and 49. A route relay 2Il---4ll controls trarlic between the signals 20 and '40, and is-provided with contacts I1, 25, 33, 34, '36 and 31.17A

route relay 4IJ-5ll controls traffic between the signals 4I! and 5D, and is provided with contacts v29, 62, 63 and 64 A: route relay 40-60 controls rcontrol buses BIL-8| and `82 which are energized with a particular polarity in accordance with the `particular route relays which are energized following the establishing of a route on the miniature track diagram.'` The switch contro1"relays 'Z are preferably of the two-position magnetic stick type, so that their armatures remain in the positions to which they were last actuated in accordance with the last polarity applied to their-individual control buses irrespective of subsequent deenergization of the buses. Various other devices are preferably associated with the switch control relays Z in the control oiiice for transmitting the switch control to the eld station over a line circuit, all of which will be pointed out more specifically hereinafter.

Associated with the signal 40E, there is suitable apparatus located in the control office to transmit a call-on signal control in order to govern the signal EDEC in the event that the trackway in advance of the signal is occupied, and it is desired to advance a train by the signal in spite of such occupancy. The apparatus in the control office required for this additional control includes a call-on button l'EPB' and a call-on stick relay MECS. The call-on button MEPB is preferably located somewhere on the operatingpanel so as to be associated with the route button MJRB, and is self restoring. It may be noted that such control might well be embodied inthe route button ABRB by providing that if such button were depressed as a push button, it would control the Call-on contact GUECB, thereby embodying both the regular route control and the special call-on control in the route button. This could of course be applied to as many route buttons as have callon signals associated therewith.

It is believed that the characteristic features and purposes of the present invention will be more clearly understood by now discussing the general operation of the system with more specic reference to Figs. l and 2, it being understood that, the detailed apparatus required to accomplish the control and interlock in Fig. 2, is illustrated more specifically in Figs, 3, 4 and 5, and will be described in detail following a description of the general operation.

General operatin Normal conditions-Although the track switches TS are usually left in their lastI operated positions, they have been shown in positions required for the passage of main line traffic (see Fig. 2). The signals are of course` normally atstop. As the signals are illustrated as being of the color light type, it is to be understood that the lower or red indicator of each signal is normally illuminated (see Fig. 5 for details).

With the track sections unoccupied, the track relays T are normally energized with their contacts picked up.

With all of the route buttons RB in their normal positions (vertical) indicated by the arrows on the buttons, the signals governing trail'c over the track-way are at stop and all of the relays in Fig. l are ale-energized.

Establishing a muta- In order to obtain an understanding of the operation of the system, we will assume that the operator desires to establish a route from the signal 2B to the signal 40E. To do this, the operator turns the route button ZURB to the right and then directs his attention along the track-way to ascertain whether the switchesA in that route are unlocked as indicated by the lock lights (mentioned above and eX- plained in connection with Fig. 4), and then rotatesthe route button MIRB to the right. The contemporaneous positioning of the route buttons 20RB and 4|JRB in right hand positions closes contacts 22 and 42 respectively in right hand positions, therebyestablishing an energizing circuit Vfor the route relay 20-40 from thel positive terminal of a suitable source indicated as through a circuit including contact 22 in a right hand position, back contact 26 of route relay 20-30, back contact 2 of route relay IIJ-4|), winding of route relay 2li-A0, contact 42 in a right hand position, to

This energzation of the route relay 2li-Jill` opens its back contacts Il and 25 which prevent the establishment of conflicting routes, as will be considered later.

'I'he picking up of contacts 3G and 31 of route relay ZU- applies positive energy from (B+) to both of the switch control buses 8| and 82, which causes the energization of the polar switch control relays EZ and 23Z respectively and the actuation of their contacts to right hand positions. The track switches are controlled by these relays, as indicated by the dotted lines extending from their contacts to their respective switch machines. This is possible because their respective lock relays llEL and 23L are still energized.

The application of energy to the route relay 2li-dll, as above pointed out, causes its polar contact 34 to assume a right hand position and its neutral contact 33 to be picked up which applies positive potential from (B+) to the signal control bus 11. Such energization of the signal control bus l1, through the apparatus described in detail hereinafter, causes the de-energization of the lock relays 23L and @5L after an interval of time measured bytheir release periods (see Fig. 5) following which, with the track switches in proper positions, the signal 20A is cleared as indicated by the dotted line 'Il' extending to such signal in Fig. 2.

The clearing of the signal ZUA allows the passage of a train over the main track 28| up to the signal 40E which still indicates stop. In other words, the setting up of a route on the miniature track diagram by actuating the route buttons at each end of such route establishes the direction of trallic and permits the movement of trafic up to the signal location represented by the last route button positioned, which in this case was the route button 4DR/B corresponding tothe signals 40.

It should be noted that the control of a route relay, such as route relay 2li-40, establishes simultaneously the switch and signal controls. Thus, in order to insure that the switchmachines SM receive their controls for a suicient period to cause their operations to the desired positions, the lock relays L are made slow acting because such lock relays are de-energized immediately following the energization of the signal control buses. However, the signals cannot clear until all of the lock relays in the route have become deenergized and the track switches in such route are in proper positions (see Fig. 3). This may be stated in a little different manner by saying that although the switch and signal controls are established simultaneously, their effective response is caused to be sequential by the means of suitable time delay period inserted in the control circuits so as to provide for the control of the switches and signals sequentially,

We will now assume that the train is ready to accept a clear signal from signal 40E but a route has not yet been established beyond such signal. If the operator desires to allow the train to continue on the main track 20! in an east bound direction he operates the route button ESRB to the right, provided its lock light is not illuminatved, which causes theroute relay 40-50to be energized by a circuit closed from through ra circuit including contact ,43'in a right .hand position, winding of route relay Ail-B, back contact 28 of route relay lll-EIL contact 5I in ay right hand-position to The energization of the route relay lll-5U closes front contact iifwhich applies positive potential from (B+) to the` switchcontrol bus 80 through these contacts of the routegrelay lill-5S and backl contact E9` of the call-on stickrelay 40ECS, which causes the clearing of the signal MEA `as soon as 'the' route is properly established, which is indicated by the dotted line 'I3 of Fig. 2, The train may then accept such signal A QEA and proceed in accordance therewith up tothe next signal governing east bound traffic. As there is no east bound signal at the location corresponding to the west bound signaltl), then the .train will proceedbeyond the .control illustrated in the present disclosure, which `isindicated as. automatic territoryl by reasonof. the track. circuit control.

Following the passage ofthe trainpast the-Stgi nal 20A, in the case above assumed,V thev operator may return the route button ZllRB to 'it'sfnorrnal position, and the same is true. of the vr'outebutlished by actuating theroute buttonsin advance f the train and the route is. put to stop bythe return of the route .buttonsto normal'positifons fthe operator may establishsuch a route byturning the-route buttons 203B and SGRB tothe right. This energizes the route relay 23j-30 by a circuit closed from (-1-), through a circuit cludng contact 2| in a right hand position-,back

Q contact I8 of route relay lll-30, windings of route relay 2li- 30, back'contact I9 of route relay Ill--- tion, to

Vof the Vmain tracks, a conicting MLback contact 25 of `routerelay 2li-Ml, contact 32 of route button 3llRB in a right hanelfposi- This energization of the route. relay 2li-30 energizes the switch control 'buses and the signal controlbuses in a manner to establish a route4 over the cross-over including the track switches 2TS and BTS by'clearingthe signal 20B for-such route after the switches have responded.

- The particular featurette -be noticed incon- Vnectionv with the establishment'of such aroute is the interlock between the route-relays. lilii;

2li-3U, lll-lll)l and 2li-4i). Inwother words., these route relays are `so'interlockedgthat ,two parallel routes for eitheredirection mayfbees-,` tablished simultaneously' over the main tracks: 200 and 2li-l, but so` yarranged so that. in the event of the establishmentof a route over one route cannot thenybe established. i

75:' `If we notice the arrangement of. contacts;

theroute just considered; namely, with the route buttons ZSRB and 30RB operated to the right, the route relay 2|] 30 opens the circuit for the route re1ayv20-40 at vback contact 26, .thus preventing the conflict of controls thatmight be existent were it possible for the actuation of the route relay 2li- 40 following'theenergization of the route relay-2il3- For example, assuming that the operator has just operated the route buttons ZDRB and lllRB,` and then operates the route buttons 4llRB and EURB, the route relay Z-AIJ might be energized were it not for the back contact 26. of the route relays 2li-3U.

Similarly, the route relay 20A-til opens back Contact i6 preventing the ,energization of the route relaylil-l-llll, and, likewise opens back contact l'preventing the energization of route relay' lll-30. Y

4 In other. words, the route relays 2&--30l and lll-titi, which areconflicting routes with regard to the twomaintracks, open the route circuitsr for each of the remaining routes, but the route'.

relays lil-30 and 20--40which are for parallel routes vopenv only those route circuits forthe route4 relays` which ngovern conijicting routes.` Thus, the route relays which are" governed by the route buttons are so interlocked as to pre- Vent any conilictbetween the. controls which are tobe set up and transmitted to the individual` traiiicgontrolling devices in the iield.

` Although the arrangement and interlock bietween the route relays controlled by the route buttons RB is notorganized to enforce or require` a de nte sequence inthe operation o f the route buttons in the establishment of a route, it is de-W sirable from an operating standpoint that the route buttons be operated in .predetermined sequences so that the'operatorI will clearly have in rnind the direction ofV traic yestablished over a route.v `For example, in the establishment of a. routeffromthe signal 20 to the signal'llil, it is desirableftgoperate to the right the routebuttons A ZiRBfand @URB sequentially in that orderfso that not only does the direction of rotation of the route buttons determine they direction of trarne and bring to the operators mind the direction of traffic which he is establishing, but also thejrnotion of his arm frornnone point tol the next definitely bringsY to mind the direction of traffic whihis being. .Set 11i)-v .The east and west boundsignals il have'been shown in Fig. 1 as controlledby a single route buttcnflRB. This has been done so kas to illustrate'themanner in which two signalsifor oppositev directions at a singlelocation can becontrolled'by a ,single route button, vand' the manner in which the signal control relays GZ .atsuCh a location are interrelated as illustrated 'in Fig.-'3.

This arrangement is particularly lclesirablefat certainnlocations in a ltrack-.layout where there may be coniiictingfroutes 'requiring.doubleV locations of thislcharacter; butin thosecaseswhere double locations of this. character are` adjacent to a. crossover` so that` in..somecases the signals control routes which lconilict. with a possible parallel routegitisdesirable to'einploy two route buttons .for such a location, as illustrated in Fig.

20ilwhilev the route button llRB hasA been .re-

v5.5 y' l placed by route buttons dllRBW and MJRBE. The route button flRBW is indicated as controlling the contacts 4I and 42 of Fig. 1 which control the same circuits as in Fig. 1; and similarly, the route button MJRBE controls the contacts 43 and M which in turn control the same circuits as illustrated in Fig. 1.

This arrangement of Fig. '7 being assumed to be included in Fig. 1 in place of route button RB, provides the more desirable arrangement where parallel routes are possible as in the track layout shown in Fig. 2, as it relieves the operator from remembering any predetermined order in which certain of the route buttons are required to be operated in complicated movements. This may be best considered by way of an example.

Let us assume that a train is approaching ready to accept a clear indication from the signal WEA, another train is standing ready to accept a clear indication from the signal 10A, and a third train isl approaching the signal 20A, which train the operator is desirous of stopping at such signal 20A. Assuming that the signals 20A and MEA are clear and the route buttons 20RB, AURBW, 4URBE and SIJRB are operated to the right, the operator returns the buttons 2RB and DREW to their stop positions in order to place the signal 20A at stop to stop the approaching train. But the operator desires to allow the train which is approaching the signal GEA to continue, so he does not disturb the route buttons llRBE and EBRB. The operator now positions the buttons lllRB and 30RB to the right and to allow the train standing ready to accept the signal IBA to proceed.

The separate control of contacts 4I and 42, and also the contacts 43 and lll bythe route buttons flllRBW and GURBE respectively provides independent control of the parallel routes at any time and in any sequence. If the example assumed above were applied to Fig 1 without the rnodication of Fig. '7, it is apparent that the operation of the route button MIRB to a stop positionrwould not be possible and still retain the signal WEA clear. Thus, only the route button ZGRB could be returned to its stop position to place the signal 20A at stop, and if after such operation of the route button ESRB, the route button IRB were operated to the right, then an undesired setting up of a route over the crossover would be effected because of the contemporaneous operation of the route buttons IURB and llRB to the right before the voperation of the route button SBRB to the right. However Fig. 1 modied as in Fig. 7 obvates such an undesired possibility.

To summarize the above, it may be stated that Fig. 1 illustrates the control of a double signal location by a single route button RB for trafc movements in connection with conflicting routes both over a single track switch and over a crossover connecting with possible parallel routes. Such control of a double signal location is entirely possible, and clearly illustrates the association of the apparatus required, but in order to furnish greater facility in the case of parallel routes a double signal location is preferably provided with two route button controls as illustrated in Fig.. 7. This'method of illustration has thereby simplified the present disclosure in that the control of two separate double locations has not `been required in the drawings, that is, a double signal location associatedrwith possible parallel routes and another double signal location shown entirely separate from parallel routes and only with diverging routes over'single track switches.

In the practice of the invention, it is desirable that it be required that a route button be operated at each end of a route irrespective of the intermediate route buttons which may be located between such opposite ends of va route for signals governing the opposite direction. In other words,

when a route is established from one signal to the next succeeding signal for that direction, it is preferable that the route buttons for such signals both be required to be operated before such route will be cleared to allow the passage of traffic, even though there may be some intermediate route buttons which will govern signals for the opposite directions. For example, the route represented by the route buttons ZURB and 40RB of Fig. 1 is illustrative of what is meant, as the signal 20A can clear only when the route button for the next signal governing the same direction is properly operated.

However, in some cases, such as in the case of signals 50 and 60, for example, the control of a train is taken away from the operator as the train passes onto automatic signalling territory, and hence, it becomes unnecessary tohave a route button representative of the end of the route of that train at the end. of such automatic territory. Also, it may be that the routes in the interlocking plant governed by such route buttons connect with unsignalled territory and thus there would be no signal at the end of such route. Also, it may be that at the particular interlocking plant head-on protection only is desired rather than complete control of the train for switching purposes. Thus, the present disclosure does not illustrate all of the various operating conditions which may be encountered in practice but rather discloses particular apparatus and mode of operation of such apparatus which is applicable to all types of track lay-outs.

' In View of the above, it is therefore proposed in accordance with the invention to indicate by different color, or by some other suitable means, whether a particular route button is representative of signals governing traine in both directions or a signal governing traic in a single direction, so that the operator will be adequately advised as to the possible control which he has over train movements.

It should also be understood that route buttons RB may be located at points where there are no signals for the purposes of providing optional routes. For example, a route might be set up from the signal 20 to the signal 40 by way of the track switches 3TS, 2I'S, ATS and ETS all in re- Verse positions. However, in accordance with the present disclosure, such an optional route is capable of being set up by use of the emergency manual levers illustrated in connection with the switch control relays Z and discussed in the consideration of Fig. 6 of the accompanying drawings.

Call-on signal controZ.-From the above description it will be apparent that a particular signal is cleared by energizing its signal control bus with positive potential from (B-|) by the route relay governing the particular route set up at that time. There are times when the automatic signals will not clear due to the occupied condition by a train of the section of track which they govern, but it still is desirable toI be able to at times send a switching engine or the like on to such section in order to facilitate the proper and desired train movements. The signal which can clear under such circumstances is termed a call- In accordance with the present invention, means has been provided in the central oiiice for clearing such a call-on signal in connection with signal 40E, when the signal indication means (not shown) advises the operator that the signal 40EA or NEB has not cleared due to the occupied condition of the track-way in advance. This can be accomplishedl by the operator only while the route is still set up by theroute buttons RB, if he -actuates the call-on signal button 40EPB. This closes a pick-up circuit for the call-on stick relay MECS, providing governing route relay is energized, byv a circuit closed with either the route relay 40-50 or theroute relay l0-60 energized for east bound traiic.. For example, assuming a route to be setup with the route buttons 40RB and SDRB operated to the right and the route relay 4ll-,-50 energized, a pick-up circuit-for the 40ECSis closed from (B+), through a vcircuit including front contact 162 of relay `lll- 50, polar contact 63 rofrelay 413-56 ina right hand position, windings of relay MECS, backicontact of push buttonUEPB, tor (CN). On the-other hand, if route buttons 4DRB and 60RB are operated to thejright and the route relay 40-60 is energized instead of the route relay l0- 50, an energizing'circuit is closed from (B+), through a circuit including front contact 6,5 of route relay 40-'6il,polar contact 65 of route relay Vdll-6l) ina righthand position, windings of'y relay 40ECS, back contact of push button lll'lEPB,l to (CN). 4, u

'I'herelay MECS .remains energized following itsiinitial energization, vby reason4 of its stick contact1j68applyingl (CN) to its right hand terminal in place of .the self-restoring push button 40EPB so long as the governing' route relay is still enery gized. f

then 'the operator may actuate the call-on button apparatus, itis thought to be suilcient for an PB associated with that routeto cause the call-on signal associated with, vsuch yroute vto be cleared.v

Itfis to be understood in this connection that although only the signal 40E has been provided with'a lcall-#on signal, thatas many call-on signals may be provided as foundjnecessary in the practiceof rthe invention. y

'Detailed operation4 'Y Switch contrOZQ--In connection with the general operation, itwas vpointed out how the actuation yof a" routeA relayffor a particular route applied lpositive or negative potential to the switch controlbusesSU, 8ly and 812 in order to energize the individual vswitch control relays Z to positions correspondingy to the positions required for the track. switches'for that route. Although` each trackswitchis provided with the same control understanding of the operation of the rsystem of kthepre sent invention todescribe thevcontrol ofr the track switch JTSrbythe switch'machine ,control relay-1Z. l With reference to Fig. 4y of the accompanying drawings, the switch control -relay IZ and its con.- trol bus vll-has'lceen `repeated therein instead `of carrying the circuits which it controls by `con-v tacts 85 and 86 across from Fig.,1.

Also, that portionof the -miniature trackdia, gram illustrated in Fig. 1 of the accompanying drawings which is representative of the track layout vassociated with the track switch' 1'IS,-has

` been'l repeated in Fig. 4` so as to illustratethe suitablytransmits its motion to the miniature switch point4 its through'a connection Ill. The normal coill N of 'the'v point indicator 'IPI is energized by reasonof the contact `,of the switch control relay 'IZy being in a normal right handp siti-on, but when-ever the contacts ofthe relay IZ i are operated to left handreverse, positions the contact |6501e course closesa circuit for,- thereverse coil R of the pointr indicatorr'lPI, as willbef obvious. In other words, each miniature track switch point indicates the position of itsswitch control relay. k t

With this understanding of *thev operationof the miniature trackswitchpoints, it may be seen` with reference to Fig. 1 that ,the operation ofthe routebuttons RB at the two opposite ends ,of a route cause allmof the miniature track switch points to immediately assume` positions in vac. cordance with *thel proposed route even before such route is actually established. over the. track layout in the eld. This provides that the operator is informed immediately as to whether Vor not it is theroute he contemplated,-and if itis no he can then quickly rectify any mistake,

It is thus seen, that, although the operatorv sets up his routes vand considers them in terms .ofcome plete routes, the controls thus effected by the operator are differentiated into the functions off'the route so that the operator may check the..indi.v

vrelay 'lLPiof theV double winding neutral type which is provided with slowreleasing character-l istics but is quick to pickup. This relay :ILP has contacts 81'v and 10Q Associated with the miniature track switch. its is a lock; indicatori Gili lamp ll which is controlled by the back contact Y 1D of relay lLPto-indicatawhen illuminated;

that theassociated track switch, is locked and will-not be operated in response vto the setting up of newcontrols. v

Thepositionoff each track switch is indicated in the. centrallofcebya switch repeatingrelay,

' which for the track switch 'ITS isfillustrated as .relay 'HWP-P,y having'contacts 88,9161 and |66;

The position -of the switch control relay 'IZ isfindicated on the control panel bythe position'of theminiature track switch point, but whether the actual track switch 'ITS is in a corresponding position or not is indicatedA bya Ycorrespondence indicator 169, which is :illuminated:` wheneventhe track switch is out of correspondence with its switch control relay TZ or whenever such track switch is unlocked. With the polar contacts |66 and |6T of the relays TZ and TWPPin corresponding positions it is obvious that there is no potential applied to front contact |68 of the relay TWPP, but whenever these contacts are out of correspondence, positive potential (-1-) is applied to front contact |68 which energizes the indicator |69, thereby indicating the lack of correspondence between the control relay TZ and the actual track switch TTS although it is locked. Whenever the track switch is unlocked, back contact |68 of relay TWPP is closed and applies potential from (-i-) to the indicator |99 directly.

These devices TZ, TLP and TWPP are preferably located in the control oce adjacent tothe switch control relay TZ, while the switch control is transmitted from the central oice to the field stationV over a line wire 38 forming a circuit with a common return line wire (not shown but indicated by the symbol CN previously explained), and also, the position of the track switch is `transmitted over a line wire 39 employed in connection with the common return wire (not shown but indicated by the symbol CN previously explained) to control the indicating relay TWPP.

At the eld station, the position of the track switch and its locked condition is indicated by the usual polar-neutral relay TWP which is energized with .positive or negative energy depending upon whether the track switch TTS is in a normal or reverse position respectively and is locked, and this relay is deenergized whenever the track switch TTS is unlocked or is being operated by its switch machine TSM. This polar-neutral ree lay TWP has contacts 95, 96, 9T and 98. The contacts 9T and 98 serve to energize the line wire 39 with positive or negative potential to control the relay TWPP, as previously mentioned.

The control for the switch machine, as received over the line wire 38, is repeated by a switch control relay TWZ, which is of the polar-neutral type. This relay is provided with contacts 9|, 92, 93, 94, 99 and |00. Contacts 93 and 99 of relay TWZ in combination with contacts 95 .and 96 of relay TWP serve to control two correspondence relays TNCR and TRCR to indicate when the track' switch is in correspondence with the switch control relay TWZ.

Associated with the relay TWZ is a lock relay TL of the slow release quick pick-up neutral type, the control of which is described more specifically in connection with Fig. 5, it being suicient at present to understand that this relay is deenergized whenever a route is cleared over the track switch TTS.

As the operation of such switchcontrol has been more specifically described in my co-pending application Ser. No. 540,596, led May 28, 1931, and certain features of which have been previously disclosed in the application of R, M. Phinney, Ser. No. 539,486, led May 23, 1931, it is believed to be sufcient for an understanding of the operation of the present invention to state that the polar contacts and 86 of the relay TZ take the place of the manually operable control lever in my prior application, Ser. No. 540,596 and apply positive or negative potential from (B+) or (B-) to the control circuit of relay TWZ whenever the relay TZ is operated to a new position out of correspondence with the position ofpolar contact 88 while the lock relays TL and TLP are both energized. If such operation of the relay TZ occurs While the lock relays are deenergized, then the relay TLP will not be again picked up until the contacts of the relay TZ are returned to positions corresponding with the polar contact 88 of the relay TWPP. This arrangement provides what is termed the electric lock equivalent or the electric lever lock equivalent, so as to prevent what is termed preconditioning, that is, the setting up of a new route after a train has accepted a rst set up route so as to provide that the new route will be automatically set up Vupon the passing of the train beyond the limits of the iirst set up route.

In other words, the front contact 8T shunts out the contact 88 when the lock relays are picked up so that the relay TWZ can receive an opposite potential when the contacts 85 and 89 are out of correspondence with the contact 88, and such reversal does not drop the relay TLP asl its windings are differentially connected.

Whenever the lock relay TL is deenergized, the contacts of the relay TWZ are maintained in positions to which they were previously actuated by a stick circuit including polar contacts 9| and 92 of relay TWZ and back contacts 89 and 90 of relay TL. y

It willrbe apparent from an inspection'of the drawings that the relay TNCR is normally energized with the relay TWZ in correspondencewith relay TWP by reason of a circuit closed from (B+), through a circuit including front contact 99 of relay TWP, polar contact 95 of relay TWP in a right-hand position, windings of relay TNCR, polar contact 94 of relay TWZ in a righthand position, front contact 93 of relay TWZ, to

When the route buttons in the contro-l oiiice are so actuated as to cause the polar relay TZ to assume a reverse position with polar contacts 85 and 86 in their left-hand positions, and the lock relays TL and TLP are energized at that time, then the contacts of the relay TWZ assume reverse positions and the switch machine TSM responds by reason of the reversal of polarity by polar'contacts 99 and |00.

Such reverse operation of the switch machine TSM operates the track switch TTS to a reverse locked position, which is indicated by the opposite energization of the relay TWP. This causes the reverse correspondence relay TRCR to be energized by a circuit closed from (-i-l, through a circuit including front contact 96 oi relay TWP, polar contact 95 of relay TWP in a left-hand position, windings of relay TRCR, polar contact 94 of relay TWZ in a left-hand position, front contact 93 of relay TWZ, to Y It is obvious, that both correspondence relays will be deenergized whenever the switch machine is in operation because of open front contact 96; will be deenergized whenever there is a lack of correspondence between the relays TWZ and TWP; and, also will be deenergized whenever the relay TWZ is deenergized.

The control of the switch'machine TSM by the polar contacts 99 and |00 of relay TWZ may be of any suitable type, such for example as shown in the application of. C. S. Bushnell, Ser. No. 408,991, led November 11, 1929. In other words the switch machine of Patent No. 1,466,903 may be controlled directly by contacts 99 and |00, or modified by the motor control of the above mentioned application Ser. No. 408,991, or any other suitable control for the switch machine motor may be provided.

Emergency switch control.-With reference to Fig. 6 ofthe accompanying drawings, a manually v so` that whenever theoperator desires rtofset up a `ently energizingthe switch 'control bus 80.l y control of the manually operable 'lever 84 must'bev operable' three-positionflever 'with 'a normal-central positionv -is= illustrated, whichlever maybe inserted atA the point inf the switch control l bus 80tindicated by:` the reference vcharacter 83 and` its-lead-line of--Fig=1 4: *The'insertion' of such iamanually operable. leverfserves 'at least twol pur-'V poses, namely, the operatorcan either control the"- `trackswitches without-thef setting vup of aroute upon the'miniaturetrack"diagramby the op'era- 'tion of'the/'routefbuttonsRR or'he can use the routev buttons cto; control the signals and use the* manually operable levers to set upr the yswitch` This of fcourse'" positions -cfA an optionaly groute. assumes thateach'of the switch control relaysZ is provided withsuch anv emergencyV manually operable lever,y as lever 84.*

This independent control forfthe track switch ITS, Yfor example, is laccomplished by the applicationf"o f positive ornegative potential from`v B4-)or '(B'-), tothe switch control lbus 80 with thev lever 84rin left hand or right hand positions c respectively," thereby-fdisconnecting'the busL 80 from the Vcontrol ofthe vgoverning route 'relays such as -relays -50 and 40-60 rand independ- Such accomplishedwhileall route relays, such as relays 40-50and r40e-|50; are-deenergized. Otherwise thelock relays 1L and "ILP would be deenergized vand preventvsuch control.

It'may be well to note `in this connection, that thelock indicator 'I| `is ,energized` Wheneverthe track-'switchJTS'is lockediagainst operation so that'the operator will 'know whenY theswitch` is locked'. Such'an indicator is associated with-each miniature track switch located on. the"^diagram route,V hescans that route tosee whether any of the lock indicators' forthat froute'are illuminated,

:randif so he does not endeavor toset up such'new `route untill-*all such indicators' are'exti-nguished.

This l'obviates thepenalty offgettin'g a switch control relay Z out of correspondencestwithits-track switch atra time that fa' lockrelayisdeenergizei although the lockfrep'eating' stick relay 'ILP 'pre-fV event that' Vents`any' undesired'results in theI `suchiwarning'is.not-heeded i the operator 'canfoperate ,thel switches independently'of route control 'buttons when such 5`0-. routs vas include thoseswitches are at stop andf v are runoccu'pied."l This provides that 4the switch .can be freed from snow and ice,for thetlike.

If I the operator' desires `v to set up'fan optional routev not controllable by the'oute:b`uttons, he

".iirst operates the manually operable 4emergency l switch control levers,v and then positions' the routebuttons at the'ends ofthe route "for-the,"

proper directi'onof traflicmovement. The signal for 'such' route vclears vonly after-the route indin 'i catingcircuits inthe eld `'(laterexplained') check:-r4

then-actual establishment of: such route;

This independent-manual control 'can also 'beY used' tcirestore'a'switch control relay Z `into correspondence withrits switchY position-indicatinglrelay WPP in Vth'efeventthe-Warning of alock'lightl is 'notheeded, and the "routefcontrol of y'a switch isflo'st. As the correspondencelamps'or indicator; such' Aas r,indic'zaton |69; are 'normally' dark, andlarecnly temporarily illuminated whilatheir 'switches f are in transit, a' continuously illuminated correspondence lampf-servesA to advisel the operatcr'as to what-switch control relay Z needs)` to be returned into correspondence with its track l switch. 1

Route rinterlocicz-With-reference to Fig.y 3 of` block form'insteadotfshowing the circuits which f;

control them: v y .f

The relays- A1L,LINC-PfandlRCR are provided I with contacts-|33;- |34 1 and |35 respectivelylfor selecting route circuits- Similarly; therelay -23Lf-v is `provided-with contacts I I 6 Vand- |22; the'` rela-yt I ZZiRCR vt'i'ithcontacty I2'I;-"the`=relay 23NCR-with'- contacts ||`I and |23;v the -relay 45NCl-'t` with contacts I8 and I' |24; the relayf45RCR 25 g.

al'ldjlzfh l l v f- Figs. 1 and 3 may be placed end to'end-so that the signal-l control bus-wiresjofVv theftwo iigures connect-together.- In other'Words;-Fig.f2 placed-car:

endto-end to Fig.1.findicates by dotted li-nes-- the,v ultimate destinationof theA signal controly Wires, while'l'ig.v -placed end-toendr with Fig; 1

illustrates,V the .detail Vcontrol vprovided in-l connectionwiththe signal control buses.

Each? signalicontrolfbus ends in a signal conv--V trol relayrGZwhichlis indicated asassociated-with-V- its respective signal by reason Y ofI like preceding numerals. 4 Y i Y, Y

' More specifically,` a signalcontrol -relay- |0GZ-isj40 t connected inthe signalcontrolfbusil and-is illustratedr as having contactsIOl, and- ||5--in thisA iigureg..of the drawingsalth'ough it listol be un derstood that fit.y is f to *have` Aadditional lcontactsffor theselectionof the signal control circuits andT 45 lock relay- ,control circuits in ,a similar mannerf v as illustrated'.specificallygfor.a signallcontrolreings'later to' be considered. Similarly,` a signal control relay v20CTZ `is Vprovided .with contacts |03 l 50 and |2-|; a-signal controlrelay.30GrZfis-provided-A with contacts |05 and|20;fa signal control relay 40WGZ is provided with contacts: |01',H |26 andy |32 a signal control relay,40EGZ is provided with ,Y

GZ' is provided with contacts .and-|3'I; a -v signal controlirelayV GZ is provided with contacts ||3.and|3|.A l y l Associated witheach of the signal control .re-fl lays GZ` and their'respective signals. is a suitablerg l route indicating relay RRwhich indicatesI when- 'ever a routeiis` established over which its associatedi-signals govern traflic. -These route indieating-relays vRR. are provided withcontacts, in addition to those .illustrated in Fig. 3, .for the 65 purpose of selecting-.signal circuits', andthe like,

so thatthe contacts illustrated with the: routel indicating relays RR .inflig- Bare onlythosefthat arenecessary for thecontrols illustrated therein. f

More specifically, a'route relay IDRRLis asso- 70 ciatedr withr signal 0 and-:is `provided -with contact |02; a routerelayl 20RR is providedvfwithy Contactv |045- a `route',` indicating :relay SURE is x provided-with contact |06; a'route relay 40W'R1'1.Y

is provided with'contacts |08 andY @129:3 at' router-75311 trol buses andsignal control bus.

indicating relay MIERR; 'is provided with contacts HG and |54; a route indicating relay 5URR is provided with contact H2; a route indicating relay llRR is'provided with contact H4. These signal control relays GZ Yandroute relays RR are of the usual neutral'type relay.

Under the heading Establishing a route, it was considered how a route is established from the signal 29 to the signal 49 by the'proper positioning of the route buttons ZURB and MRBJout onlythe general results obtained were considered subsequent to the energization of the switch connow desired to consider more in detail the operations involved in the establishment of this route following the energization of the switch control control buses v8| and 82 thereby actuating the polar contacts of the relays 45Z and 23Z respectively to their normal right hand positions, if they are not already in such positions. Such actuation of the relays V-flZ and 23Z causes the control of their respective switch machines and track switches in a manner similar to that pointed out more specically in connection with the track switch TTS.

As the track switches are considered to be unlocked at this time, and the relays Z having been in correspondence with their relays WPP, the switch controls are transmitted to the WZ relays and thence to the switch machines. Such control istransmitted to the WZ relays only whilethe lock vrelays L are still energized, that is, are dropping away subsequent to the opening of their energizing circuits. As the lock relays are made` (B+), through front contact 33 and polar contact 34 of the route relay 20-40, signal control bus A'|'|, windings of the relay 2UGZ, back contact |94 of the route indicating relay 2|!RR, to (CN). As soon as relay ZEGZ responds, it closes its front .contactY |93' rendering it entirely dependent for 45L may be seen by analogy toy Fig. 5, later to be explained, wherein it is shown that the lock relay 1L is deener-gized whenever a Vrelay GZ ence with theV relay '|WZ, a route circuit is comgoverning traic over its track switch is picked up.

As soon as the lock relays are deenergized and the track switches have come into correspondence with their WZ relays as indicated by their correspondence relays NCR and RCR, then a route circuit is completed for the route indicating relays ZBRR and lllWRR closed from (-l) through a circuitl including front contact |2| of relay MGZ, windings of relay 2|]RR, back contact |22 of relay 23L, front contact |23 of relay 23NCR,

front contact |24 of relay 45NCR, back contact` |25 of relay 45L, windings of relay llllWRR, back contact |26 of relay GIJWGZ, back Contact |64 of relay QDERR, tol

However, it is As soon as the relays-ZORR and MIWRR respond, a stick circuit is completed including front contact |29 of relay SDWRR so as to eliminate the control of the relay dERR, as such relay is energized whenever the route is completed between the signal 4|] and either the signal 50 or the signal 60.

When a route is set up from the signal MEA to the signal 50, the relays GDEGZ and HERR are picked up, so that the route indicating circuit, just traced above, can be completed at any time nor is it broken by the clearing of signal (NEA. But when the signal 49EA is put to stop by the deenergization of the relay QOEGZ, the contacts |3| and |54 open sequentially in that order and the stick contact |29 prevents the deenergization of relays GDWRR and 2|lRR.

On the other hand, if a route is set up from signal 50 to the signal MWA, the relay MBERR is picked up while the relay 49EGZ is deenergized. This causes the route circuit for relays 20RR and GIJWRR to be maintained open at back contact |64. This prevents the opposing signals 29A and 59 from being cleared at the same time. It is of course seen that if the signal 29A were cleared rst, the signal 50 would be prevented from being cleared by reason of open back contact |29.

Let us assume that the operator desires to continue the route from the signal to the-signal 59, as considered under the heading Establishing a route. The switch control relay |Z is actuated to its normal position following the positioning of the route-buttons RB, which relay '|Z controls the relay 'lWZ to the normal position, in a manner previously described, so that the track switch 'ITS assumes a normal position in correspondence with the relay |WZ`. Also, the energization of the signal control bus 13 causes the relay AUEGZ to be energized through a circuit including back contact ||U of relay lilERR and upon its picking up closing front contact |99, so that the control of relay 40ERR by contact l0 is eliminated.

The energization of the relay 40EGZ opens the energizing circuit of the lock relay '|L, which is shown in Fig. 5 as a circuit closed from (-1-), through a'circuit including back contact |49 of relay 50G, back contact |50 of relay SDGZ, back contact |5| of relay 50GZ, back contact |52 of relay MEAG, back contact |53 of relay llllEBG, back contact |54 of relay 49ECG, back Contact |55 of relay IMIEGZ,V front contact |55 of track relay 1T, back contact |5'l4 of relay 50G, windings of the relay 1L, to Y Although the switch bus 80 is energized simultaneously with the signal bus 13, the relay TWZ has plenty oi time to actuate its contacts to their proper positions as relay 1L is slow releasing, previously mentioned. With the relay lL deenergized and the relay lNCR energized because the track switch TTS is in normal position in correspondpleted for the route indicating relays 40ERR and MRR from (-1-), through a circuit including front contact |39 of relay MEGZ, windings of relay ilERR, back contact |33 of relay '|L, front contact |34 of relay lNCR, windings of relay 59RR, back contactl |31 of relay SOGZ, to The picking up of relay lElERR opens back contact H9 and back contact |54, but as the relay 49WRR is picked up, its front contact |29 maintains itself energized to its selected route circuit, and also the closure of contact |99 eliminates the control of contact H9 for the relay QDEGZ. The energization of theV relay 50RR opens its back Cil ` contact 2 preventing improper control of the relay 50GZ.

(with-the route circuits thus established, the

Vrespective signals `are cleared, that is, with lthe relays ZUGZ and ZURR- energized, with the track 1 switches'zrs, srsrrs and 51's in normal positions, the signal A isV cleared; while with the relays 40ERR and 40EGZe1iergizedwith the track switch'lTS ina normal position, the 'signal 40EA is cleared. Althoughcontrol circuits have not been shown for signal 20A, it is to be understood they are similar to those specically illustrated in connection with the control of 4signal 40EA in v Fig, 5 of the drawings and eiplainedunder fSignal selection.` 'I t is to be understcodthat simi` lar *signal V`control circuitselections are Amade in 'ccnnecticn with eachfof*` the signals of the track layout.

1t is believed that the controlof the various y,the consideration of the route circuits already p'ointedpout, `it/lceing sufiicient for further underoth'erroute circuitswillbe readily apparent from standfmg ,of such route ,circuits to merely point out the completion of certain typicalones.A For example, let us consider theroute lcircuit j closedwhenf it is contemplated to clear'the signal SilB to allow 'the passagefof vtralc over the,-v crossover including track switches 2TS and STS rtotheV signal A2|l.- Under such circumstances the 'signal control [relay 30GZ is picked up, which,- closes the4 ro'uteindicating circuitY forfthe route indicating `'relays .3URR and ZURR ,fronrf (-1-) througha circuit including front Contact 12B of.V relay 30GZ, Windingsof relay `30RR',fback"co'n tact- ||9 of relay Il SLQfront contact v| 8 of relay f clearing'ofsignalsin Fig. 5.

contact,|22lof'relay 23L,` windings ofrelay ZORR, back Contact. |2 ;ofre1ay 20GZ, to "(k-). The manner in which the/relays 30GZ and BORR clear v the signal 30B will b e readily'understood by analogy of'vthe.-description given with regard to the `11; is also desired to. pointvouaffhatthe bpncnarroutefoverl the. track switches 2TS, '3TS, ATS' and TS in reverse positions is'providedwith a l route indicating circuit, although the route buttons RB' do Inot..ther'nselves vcause the switches to assume such positions' but ratherithe operation of theindividualmanually,operable emergency controllevers, 'asprev'iously mentioned: For examplegassuming the `.signal 2|iBvis to vbe'y cleared vfor the ,passage of traic over suc:1f1'voptior1a1` route,v

l the relaylGZ isenergized byl the positioning'of thejroutet buttonss'ZSRB" and]A llllRB @to the^right following.'V the. positioning of 'the manually oper# able emergency swit'chcontrol.'leversQfV-such as;

l lever l|311, (seeFig..6)f. `With therelay ZilGZvpicked up, andtheswitchesintheir proper positions as indicatedby the correspondence relays `ZSRCR.

and" ABRCR, a route indicating circuitis closed from (-i-)througha circuit including front-coni" tact |2-iof 'relay NGZ, windings of lrelay 2|ljRR,

` back contact .|22 of,` relay ,23L,'- front Contact E21v of relayy 23RCR front contactl |28 of relay llRCRgf back contact "|25 of rrelay 451'., windings offrelay" MWRR, back `contact |26 of 'relay `40WGZ,.back

sponse ofthe relays" ZDRRand'UWRR'closes the Afront ,Contactv |29 of relayflillWRR whichvvelimi-'v`v g nates'thefcheck thatback contact V|64 of'` relay MJERR provides to insure that ,thesignals and 60 are at'stop. The manner` in which the` .signal v28B is cleared 'uponthe' energization o1"tl'ieA relays ZUGZ andfZBRR will be` readily apparent of itsv associated signal.v I l Signalyljis Dipl/ided with al control relay G of the by analogy of ther description givengwith regard to Fig.1"5.'f x l Itis desired toagain point out that no indicata ing route circuit can be completed for routeindi-i eating relays RR until the vtrack switches'arein correspondence with their respective relays WZV in spite ofv the fact vthat their respective lock relays.

Lim'ay loeI denergizedas soon as-the signal con,- k y trclfrelays GZvreceive energization. Injthis connection underv the heading Route interlock it is desired to point out that such` route indicating'circuits provided to indicatewhen al route has: been established, are disclosedand claimedin my prior application, Ser.` No.. 540,596, filed May 28, 1931, and in the .application ofLarry and Langdon, Ser: No; 577,504, filed Nov. 27, 1931,

the'present disclosure being made for. the purposey of showing-ftheinterr-elation between such route indicating circuits and theV features of the present inventiongit` also beingunderstood that these new present-invention and the route circuits thus shown" herein are application..v .1 .4

` S'vzfgprtl seZectz'onsg-Referringvto Fig. 'offthe intended Atobe claimed inthis 20 relationships loetwee'nthe control provided by the .l i

'accompanying drawings, that portion of the track vlay-out including the track switch 'FTS hasfloeenl repeatedmfor..convenience in considering the 'cir- "cuitsshcwn, in Fig'. 5. Thesignal control-relaysA llSGZBUGZand @GGZ havebeenrepeated Afrom Fig`.3andfshown in'lolock forrn ,for convenience v V in ysljiowirig (,:ertainy circuitsfwhich they control. :'zSimilarly, c the v route indicating* relays MBERR,

spondence relays for krthe track switch l|TS," namely,r relays 'INCE and IRCR havebeen re'- peated from 'sito illustrate their control in the signalcircuits'. *Alsoftrack relays 7T, 3T and 9T,

indicated in Fig.w2;of the accompanyingdrawings,

hayelbeenrepeated for convenience.

each signal arm with its reference character coni taining a G` preceded 'by the reference character neutral type which when de-energized causes the red indicator. Rto 'be' illuminated, and which when... energized' causes the green or clear Vindi- In other words, each cator Gto be illuminated. In this connection, it j isjto be understood that if home and distant relays'. are employed that green and yellow indica-- v tions 'may benprovided in accordance with the risticii` practice'vbut such control has not been illus- ,tratcdglfor the'purpose of making the disclosure as simplev as `possi-ble. Y v n We will now consider yhow vthe signal 4DEA is t. clearedffollowing the energizaton of the 'relay AERR., 4Asl the relay MIEGZ isv energized with positive potential from (B+) through front contact v'620i relay 40-50, vover signal control bus 13, the polar contacts of the relay llEGZ assume "right, hand positions.v with the track switch i'rs vin anormal position, the'energizing circuit for` thesignal relay AEAG is'then closed from l(-i) through aj circuit including iront contact. |38

of relay MEER., front contact |39 of relay 40EGZ,

polar contactA |40 of relay ABEGZ in `a right hand position, front contacty MI of track relay lTfront Contact of track relay. 8T, front contact |43 'ofvrela'yJNca windings 0f relay a'oEAG, to ,-f).

' As Vsoon as the relay QUEAG picks up, the red indicator ofthe signal MEA is de-energized` byv Yso reason ofthe openingf'of` back contact 58;' and@i the 'green indicator is energized by reason` of the closure of front contact'158.y With thesignal thus cleared, the `train may` proceed in accordance therewith. y

In a similar manner the relay dEBG controls the signal 49EB by contact |59;V the relay 40ECG controls the signal 4|EC by contact |60;l the'relay' vof the actuation'` of the route'button 5|lRB, then the relay lliEAG would not be energized but the relay 48EBG would be energized by reason of the energization of vthe relay lRCR instead of the relay lNCR.

For example, the circuit for relay 40EBG would then be closed from (-l-), through a circuit including frontcontact |38 of relay 49ERR, front contact |39 of relay 40EGZ, polar contact |40 of relay 48EGZ in a right hand position, front contact lill of relay lT,front contact |44 of relay 9T, front Contact v|45 of relay 7RCR, windings of rela 4U EBG,to(-). i

For the purpose of simplicity in the drawings,

the signal relays 50G and 80 G have not been illustrated 'as being `provided with track circuit control or 'otherselections Thus, the relay 50G is controlled only by the relays 5DGZ and 5||RR so l that when the contacts|62 and |63 of these relays Irespectively are closed, the relay 59G is energized and the signal 59 is cleared. This of course can occuronlywhren the route is established in the opposite direction from that above explained by reason of the actuation of the route buttons 50RB and 40RB to the left.

Similarly, the signal relay BUG is energized when the relays GUGZ and BORR are picked Vup to close their respective contacts |41 and |46, when the route buttons pRB and 4DRB are actuated to the left.

It was pointed out under the heading Call-on control, that the energization of the signal control lbus -13 with negative potential'from (B`-),

through front contact 69 of the relay llllECS, ,caused call-on signal MEC to clear.

It can now be seen that such energization of the signal control bus 'i3 causes the relay 4DEGZ to actuate its polar contact to left vhand positions (see Figs. 3 and 5) which causes the energization of the relay 4DE'CG (see Fig. 5) instead of either of the relays 48EAG or 40EBG. This energizing circuit is closed from through a circuit including front contact |38 of relay 4ERR, front contact |39 of relay llVDEGZ, polar contact |40 of relay MEGZ in a'left hand position, windings of relay 4BECG, to It is seen that this energizing circuit for the relay 40ECG, which controls directly the signal 40EC, is independent of track circuit control and such call-on signal control is used only when the upper arm signals 48EA and 40EB are not capable of being cleared by reason of trains in advance of such signals.

Although only the signal relays GZ and G with the track relays T have been shown as controlling Athe lock relay 1L, it is to be understood that any other suitable usual selections may be inserted, such as the use of directional tumble-down stick relays as shown and described in the application of Stoltz, Ser. No. 402,527 filed October 25, 1929, together'V with features of approach and release ing inthe direction of the arrows.

route locking. This-has been omitted for the sake-` of simplicity.

M odijecl control panels-With reference to Fig. 8 of the accompanying drawings, the control panel of Fig.v 1 and the route circuits shown therein are modified by the provision of a different type of route button. This provides that the establishment of a route requires the actuation of the route butto-ns at the two opposite ends of such route, but the returning to stop of such routerequires the restoration of only the route button corresponding tothe signal which cleared for that route, -as the route button at the opposite end of such route is automatically restored to normal following its actuation.

The same miniature track diagram is repeated l connection with Fig. 7, has been lapplied to this modified form.

Each of these route buttons comprises a structure more specifically disclosed in Figs. 9 and 10 of the accompanying drawings to which reference should" now be made .to obtain an understanding of the operation of these buttons before considering thegeneral operation and control of theroute circuits and relays.

Referring to Figs.V 9 and 10, a route button, such as route button |0RB2, has been shown in detail. Such a route button is mounted upon a panel 220, and includes a shaft 22| which passes through the panel and which can be manually rotated by grasping a knob 222.

On this `shaft 22| is a collar 223 which has mounted therein anpin 224. The collar 223 can be adjustably fastened to the shaft 22| by a set screw 225 4to thereby be rotated when the shaft 22| rotates.

A lever 22B is mounted on .the shaft 22| in a manner to freely rotate except as engaged by the pin 224 of'thecollar 223. This lever is held in V place on the shaft to engage the pin 224 by a collar 22'! which is pinned to the shaft.

A xedstop: 228 is located on one side or the other of the movable lever `226 depending upon whetherr thebutton is to be biased in one direction orthe other, and the lever 226 is biased against this stop 228 by a spring 229. The spring 223 is' pivotallyattached tothe lever 226 at one end and is `suitably attached to a iixed point at the other end, which fixed point is suitably chosen with regard to the fixed stop 228 so as to provide a continual bias on the lever 228. The button illustrate-d has been chosen as what may be termed a left hand biased button illustrated in Fig. 8 asthe button IDRBZ for example, as vsuch button is caused to be biased away from its left hand position. Thus, the stop 228 is to the right of the lever 225as viewed in Fig. which is a sectional'view taken on line Ill-I0 of Fig. 9 look- Also, the pin 224 of the collar 223 is adjusted to be on the right of the lever 228. Thus, as the route button wBB2 is rotated tothe right (as viewed in Fig. 8), the collar 223 rotates counterclock-wse (as viewed in Fig-l0) so that the pin 224 does not engage the lever 226. This allows the knob 222 2o. 1 contacts are made so as to complete such circuits ras might be desired.

. of the arrows.

` 2,121,846' `and thecontact arms','sucl`1-as arm 230, to'remain inftheir last operated positions.

O n the other hand, if the knob 222 is rotated counter-clock-wise (as viewedin. Figs. 8 and 9) i the pin 224 engages the lever 226 `and causes the spring 229 to stretch.' Thus, as soon as the operator ceases to grasp ther knob 222 the tension of spring 229 causes the lever 226 to engage the y `pin 224 and rotate'the shaft 22| and'its assol=v anormal positions until the lever 226 engages the ciated contactlevers, such as lever230, to their stop 22,8. k v

' It is obvious that as many contact 'arms may be connected to thershaftas desired and each made independent of the otherby suitablev insulating materials all of whichgmay be constructed in any `desired manner. y e -standing of the present'invention tov know that It is sufficient for an underwhenl the `knob 222 is rotated in either direction for a suflicient angle, such as 90 lfor example,

In Fig. 8, the route buttons have been illustrated conventionally so that each contact is in- -dicated as having a spring bias in-a particular direction with suitable stops as just described in connection with Figs. 9 and 10, but the conventionalshould vbe considered as a sectional view looking from the knob toward the'back (see Fig. 9) instead of on, the line |8-|0 in the direction This .gives corresponding rotational relationships between'the knobs and the contacts. Also, biasing means has been shown for each contact of a route button instead of showing a single bias forone route button as would probably beemployed in practice. This is'done 1 cussed; Each of these route relays, such as relay [lil-A39 `for example, is considered yto have, thesame contacts'as shown in Fig. 1, suchv as contacts 52, 53, 54r and 55, for controlling the ener- J50- gization of the signal and switch control buses.

More speciiically, the route relay 0-30 is proi' vided with additional contacts r|8||and |8|v; the

route relay 28-30 with contacts I82-and |83; the relay lil-46 with contacts |84 and |85; the relay J21h-,440 with contacts 86A and |81; therelay 40-50 with contacts |88 vand |89; the relay 40e-60 with f contacts |90 and |9I.

, v.Associate-d with each of the route button con- Jtrolling contacts is `a suitable resistor which pre- Nventsthe shorting of the battery source, as more speciically pointed out hereinafter. Thus, a plui rality of resistors are provided and include re- Itis to be understood, that those features pointed out in connection with Fig. l of the .accompanying drawings which are not specifically pointed out in connection with Fig. 8 `as being diilerent, are considered to besimilarly assoelated with' this modified structure of'eontroi. lFor example, it was pointed out inv connection withV Fig. l that eachof the miniature track switch points has associated therewith a suit'-r able loc'kj light as described in connection with ,i Fig. 4 ,of the accompanying drawings. All such right hand position,v

characteristic features will notxbey furtherfconsidered.

f Consideration will now given tothe novelz y Ymanner in which the routes are established.

For example,v1et us assume that the operator desires to establish a route from the signal 20 to thesignal 40 by clearing the signalwZllA. To

do thisv the operator actuates the route button 26RB2 to the right in which' position ittremains,

and. following which the operator actuates the 'route button 49RBW2 toV `the right,fbut which buttonreturnsto its, normal position as soon as the operator removes'his hand.

During the contemporaneous actuation ofthe route buttons ililRB? and 40RBW2, a pick up circuit'is closed for the-route relay 20-40 fromthrough a` circuit includingv resistor |95, contact 222 in a right hand position, back contact 26 .of relay 28-.30,back contact 21 of relay iii-49, windings of relay Ztl- 40, contact 422 in v a right hand position, to (-4). k

'This energization of the relay 20-40 causes its polar Acontact |81 to assume a 2right hand position and its neutral contactl 'tov be picked up, which thereby completes' a stick circuitfor the relay Ztl-lil from (-1-) through a circuit including resistor |95, contact 222 in a right hand position, back Contact 26 of relay-2|l-30, back contact 21'of relay Ill- 49, windingsof relay 2ll-4U, polar contact |81 of relay 20-'40 in a As the relay zc-aa is ythus energized through its stick circuit, the contact 11,.22k mayreturn to its normal position automatically in accordance with its structure as above described, but the yrelay 28%,49 remains energized wholly dependent uponthemanual return of theroute button 20RB to a normal position. e

The energization of the 'relay 20--49 and the actuation oi its polar contacts to' positions in of the' route buttons 20RB2 and ll'RBWZ, causes the switchmachines ZSM, BSM, 4SMf and ESM to Vbecoiitrolled in accordance with the required normal positions for main li-ne traiiic after which the signal 29A is cleared, all of which has been vdescribed in connection with Figs. 1, 2, 3,4 and5.

It is obvious, that if the routebuttons 26RB2 and flilRBW2 are actuated to the left for the es,- tablishment of a route in that direction,'the con- `tacts of the route button MIRBW2 will be'the vones'V to remain in their actuated positionswhile the ones to return to their normal positions. f

In such a case, the route circuit would be ener' Agzed by a circuit closed from through a circuit including'resistor |99, contact 42,2in a left hand position, windings of relay 2li- 49, back l contact 21 of relay lll-40, back contact 26 of vrelay 2li-36, contact 222, to f Such an energization ofthe relay 2 ii--llllI causes its polar contacts to operate to the left andits neutral contacts to be picked up. Thiscloses a stick circuit for the relay 20--40 from' through acircuit including contact 422 in a left handk position, windings of relay 2940,'po1ar contact |81 of relay 20-46 in a left ha'nd'posi-l tiendront contact |86 of relay '2D- 40, to This stick circuit then'causes the relay 20-40 to be wholly dependent upon the manual restoration of the route button 40RBW2. y

It is apparent from the abovefdescription that each .ofthe route relays is provided with a pick up VAcircuit' corresponding toits energizing circuit 30., front contact |86 of relay 'accordance with the direction ofltheactuation Y `the contacts for the route button ZRBwillbe 

